Most of these are moddable (like anything to do with textures, or object placement (you play FSX by chance?)), so will be done eventually by someone. If I ever learn how to, I would love to get started on asphalt and concrete variations. Kelvin is doing great work on different ground textures (summer textures give a more burnt look I think, available... somewhere.) and biomes, and I guess water textures will be covered similarly (with coral etc, you mean like REX has tropical water textures?).
Accuracy in physics is being looked at, and when we get weather, raindrops should collide properly, and dirt turning into mud is definitely in the pipeline. I agree with your 'wear-and-tear'ed textures, particularly with FSX everything looks brand-new, whereas every vehicle (not just planes) is never like that.
There is a 'make shiny' function somewhere in the files for the materials, it's part of making a chrome look.
Traffic and weather may well be third-party. I don't program so I don't know if doing it for free is easy or not
Anything I haven't covered will eventually be included (I guess). Or, I hope so!